The State Bank of Vietnam (SBV) adjusted the central exchange rate slightly, dropping it by 9 dong from VND 25,249 to VND 25,240, Monday.
The Google Finance mid-market rate also dipped 25 dong over the same period, falling from VND 26,220.02 to VND 26,195.
Black market premium continues to widen
Despite the modest official changes, black market rates held firm.
The mid-market rate remained at VND 26,445, pushing the spread with the Google rate from 225 dong to 250 dong.
This widened the black market premium to 0.95 percent, up from 0.86 percent, suggesting persistent informal demand for US dollars.
Short-term interbank rates jump
Interbank interest rates rose sharply, especially at shorter tenors.
Overnight rates climbed from 3.35 percent to 5.36 percent, while 1-week and 2-week rates rose by over 1 percentage point each.
The 3-month rate increased from 5.02 percent to 5.46 percent, reflecting tightening dong liquidity.
SBV ramps up reverse repo operations
To ease pressures, the SBV expanded reverse repo injections.
Seven-day operations jumped from US$306.19 million to US$464.94 million, while 28-day repos increased to US$338.77 million.
Meanwhile, 14-day repo activity dropped sharply, suggesting a shift toward shorter-term liquidity support.
Liquidity pressures mounting amid FX stress
The combination of rising short-term rates, sustained black market premiums, and increased central bank intervention indicates growing liquidity stress.
Market watchers will be monitoring closely for signs of further SBV action or foreign exchange stabilisation measures.
See also: How Low Can the Vietnamese Dong Go? Why it’s Sliding & What Might Happen Next